This invention relates to material handling and more particularly, to conveyors. Ongoing efforts to increase the efficiency and output of production operations have resulted in a continuing focus on how materials are moved with respect to machines and other process operations being performed. Often materials are moved on conveyors between the load and unload stations of machines or other process stations, and preferably, the conveyors extend in a straight line path between the load and unload stations. However, as will be appreciated, floor space and floor layout considerations do not always permit such convenient conveyor routing; and instead, conveyor paths are designed to transport workpieces in multiple directions, for example, mutually perpendicular directions. Powered belt-type conveyors utilize generally horizontal flat belts, and such belts are not readily routed around corners. Therefore, a multidirectional belt-type conveyor path is comprised of multiple powered conveyor belts which are abutted end-to-end and oriented to move in the desired different directions. In some applications, items may be dropped from the discharge end of one conveyor moving in a first direction onto a load end of a second conveyor moving in the different direction. However, in other applications, a third material handling device, for example, a pick-and-place robot may be used to move the items from one conveyor to the other. As will be appreciated, a multidirectional belt-type conveyor system requires multiple belts, multiple belt drive motors and various sensors verifying the transfer of an item onto and off of the conveyor. In addition, if a pick-and-place robot is used, there is substantial additional cost in the application of the robot. For example, such a robot may add a motor, two cylinders, up to ten sensors and a cycle control to the overall conveyor system. Further, as the number of devices, motors and sensors increase, the conveyor system costs proportionally increase and the system reliability proportionally decreases.
Generally, the operation of a conveyor system is synchronized with the operation of a machine at a conveyor load station, and often the operation of the conveyor system is noncontinuous and incremental to match the processing of discrete workpieces by the machine. To coordinate the operation of multiple conveyors and interconnecting robots to match the desired incremental operation of an associated machine is also complex and expensive to implement. Such complex conveyor systems have another disadvantage in that they are often physically large since they are serially connected stand-alone units. The large size consumes significant valuable floor space and often impedes access to areas of a machine requiring maintenance or other periodic attention.
Consequently, there is a need for a material handling system that does not have the limitations and disadvantages of known conveyor systems for moving materials in different directions. There is a need for a multidirectional conveyor system that is simpler, less complex, less expensive and more reliable than conventional multidirectional conveyor designs.